This invention relates to batteries and, more particularly, to a system for controlling the charge state of a multi-cell battery.
In recent years, there has been considerable effort directed to developing electric automobiles. One principal problem has been obtaining accurate information about the amount of energy still available in the batteries of such vehicles. Another has been to operate such vehicles in such a way that the energy in the batteries, and the batteries themselves, are used in an efficient manner. The present invention makes electric automobiles a possible and attractive option for the consumer.
One principal object of the present invention is to provide a system for controlling a multi-cell battery according to what I have found to be the six important operating parameters identifying the charge state of the battery, thus making it possible to operate the battery near its optimum level, prolong its life, and increase its efficiency. A second is to inform the operator of a battery-driven vehicle of the usable life-time (i.e., amount of charge) and number of cycle life times (i.e., the number of times the battery can be recharged from an external source) of the battery.